Reland "De-SkScalar SkRect"

This is a reland of commit 807697510bdccddb759d0156cf68808652c61df6

Inlined sk_float_midpoint in previous CL. This should
avoid the linker error in Chrome.

Original change's description:
> De-SkScalar SkRect
>
> Change SkRect over to using floats instead of SkScalar.
> Introduced sk_float_midpoint to handle some of the
> calculations.
>
> TODO:
> * rename asScalar -> asFloats possibly? Separate CL.
> * what to do with all the scalar string stuff in dump.
>
> Change-Id: I8416f17654d9e73ff094d4c5a42ac2669389ceda
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/714063
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Herb Derby <herb@google.com>

Change-Id: I382a9532cd39edec72e5b1226eb9a12db704c568
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/714578
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed